Screw driver



March 20,1934. N, v, @OT FF 1,951,652

SCREW DRIVER Filed June 1933 INVENTOR Patented Mar. 20, 1934 UNITEDSTATES- PATENT OFFICE scnnw nnrvnn Nicholas V. Fedotofl, Lynbrook, N. Y.Application June 15, 1933, Serial No. 676,034

6 Claims. (01. 145-5 This invention relates to screwdrivers and has forits object facilitating the application of a screwdriver to a screwhead.

In accordance with this invention resilient means is associated with thedriving blade of a screwdriver which maintains a relatively tightengagement of the blade with the slot of ascrew. By virtue of thisresiliently tight engagement with the screw head, it is possible to usethe screwdriver in many relatively inaccessible positions where it wouldotherwise create considerable difllculty.

The invention is carried out by bifurcating the driving end of thescrewdriver blade, and fastening within the space between the twobifurcated portions a resilient spring-like member which is almost, butnot quite, co-planar with the blade portions. When inserting thescrewdriver within the slot in a screw head, the resilient member isstrained so that continual pressure is exerted by the screwdriver bladeagainst the walls of the slot; thus serving to prevent any inadvertentdisengagement from the screw head. The fact that the driving blade is.bifurcated does not reduce the strength-and rigidity of the blade belowthat required for ordinary operation, for no metal is removed from theedges, which are the realdriving-portions.

Although the provision of a screw driver havao ing means for effectingtight engagement with a screw head is, broadly, not novel, theparticular arrangement of this invention is believed to be novel,wherein the engaging means is resilient, and the driving portions of theblade are not substantially weakened by the resilient grippin'g means.

Another feature which may or may not be incorporated, as desired, is theburring oi the engaging member of thescrewdriver; this feature 40serving to further prevent unintentional removal of the screwdriver fromthe screw slot.

For a better understanding of the invention attention is directed to thefollowing detailed description and the accompanying drawing, of

which Fig. 1 shows a screwdriver having a blade embodying the invention;and

Fig. 2 is a side view of the screwdriver showing the blade partially insection.

Referring to this drawing, the screwdriver comprises a body portion 1.having mounted on the upper end thereof a handle 2. The lower end of thebody is formed into the screwdriver blade at 3 in the usual manner.

In accordance with this invention there is prodesirable to burr theouter lower edge of the vided at the central portion of the drivingblade a slot 4 which may be formed by removing a narrow strip of metalalong the longitudinal axis of an ordinary screwdriver blade, thusbifurcating the driving blade. The length of this slot may convenientlybe about one-half inch, more or less, depending upon the size of thescrewdriver. There is drilled a hole, or channel, 5 of small diameteralong the longitudinal axis of the screwdriver, beginning at the end ofthe slot 4 and extending upward toward the body. It is advisable,although not absolutely essential, to drill a hole 6 transverselythrough the blade at the upper extremity of the longitudinal hole 5.

A resilient wire spring 7, of the proper length to extend from the hole6 to the driving end of the blade, is forced through the longitudinalhole 5, as shown. It may be desirable, particularly if the wire springdoes not'flt tightly in hole 5, to fill the transverse hole 6 withsolder to secure the upper end of the wire spring, this being one of thefunctions of the hole 6. If desired, instead of applying solder, theupper end of the wire spring may be bent or flattened in hole 6.

The wire spring '7 does not lie flush in the slot between the twoportions of the bifurcated blade, but instead, is slanted or curved sothat the lower end thereof protrudes beyond one of the flat faces of theblade, as shown in Fig. 2.

In operation, the screwdriver blade is inserted into the slot in thehead of a screw 8 by straining the wire spring '7 toward the face 01'the blade. when in the screw slot, then, the spring action will cause acontinual pressure to be exerted by the driving blade and the springagainst the sides of the screw head slot; thus tending to hold thescrewdriver in position.

To increase the gripping action between the screwdriver blade and thescrew slot, it may be sideration is to maintain the strength andrigidity of the outer portions of the blade; and no material is removedfrom the outer blade portions by the arrangement of this invention.

,The addition of the spring member 7 into the slot ofthe screwdriverdoes not substantially increase the outside dimensions of thescrewdriver, 110

obscure visibility or otherwise hinder the application of thescrewdriver.

I claim:

1. A screwdriver comprising a rigid driving blade provided with alongitudinal slot at the driving end thereof, and a resilient member ofless thickness and much less rigidity than said blade, fastened withinsaid slot and normally protruding beyond the flat surface of the bladeat said driving end, whereby said blade and resilient member cooperateto firmly engage the slot of a screw head. a

2. Ascrewdriver comprising a rigid bifurcated driving blade and aresilient wire of much less rigidity than said blade, situated nearlylongitudinally within the slot between the bifurcated v portions of saidblade, said wire being fastened at its uppermost end and protruding atits lower end beyond the fiat face of said blad I 3. A screwdriveraccording to claim 2 in which a burr is formed on the edges of thebifurcated portions of the blade at the side opposite that from whichsaid resilient wire protrudes.

4. A screwdriver according to claim 2 in which burrs are formed on theprotruding edge of said wire and on the edges of the bifurcated bladeportions at the side opposite that from which said 7 driving end by alongitudinal slot extending substantially along the longitudinal axisfor some distance, a hole formed longitudinally in said blade beginningat the upper extremity of 'said slot and extending toward said bodyportion, and a resilient wire having one end inserted through said hole,the other end of said wire extending toward the driving edge andprotruding beyond the flat driving surface of the blade.

6. A screwdriver according to claim 5 in which a transversehole isformed through said blade at the upper end of said longitudinal hole,the upper end of said resilient wire extending into said transversehole, said wire being secured at said transverse hole.

NICHOLAS V. FEDOTOFF.

